The overall objective of the proposed work is to establish the basic biochemical characteristics of the major catalytic components of the insect (southern armyworm, Spodoptera eridania) microsomal oxidase system and to study the interactions of the system with various foreign compounds. It is proposed to solubilize and purify the cytochrome P-450 complex from armyworm midgut microsomes and to characterize more fully the multiple forms of hemoprotein which have already been shown to exist following induction with various materials. Reconstitution studies with the purified cytochrome P-450's, NADPH cytochrome c reductase and phospholipid will be conducted.